I. Field of the Invention
The present invention relates generally to digital photography and, more particularly, to the use of digital cameras and a method for detecting the presence of foreign objects such as dust, dirt or other debris on the imaging sensor of digital cameras which affect print quality.
II. Related Art
It has been found that the quality of prints produced from image data files created by digital cameras is adversely affected by the presence of dust on the imaging sensor arrays of the cameras. This is because such imaging sensors can serve as small particle attractants. In fact, a large proportion of defects requiring retouching or retakes in photographic studios which use digital cameras is caused by dust spots. The dust producing the spots is typically found on the imaging sensor of the studio camera and the existence of the problem generally is not visible to studio associates previewing orders on a computer screen prior to printing the pictures because of the lower resolution of the images displayed on a computer screen. As a result, the studio can take several days worth of customer images before a dust problem is revealed in associated output prints at the production plant. This may further result in a rather large number of printing orders having to be retaken once the problem is identified and corrected. Therefore, it would be very desirable if a method of checking for dust at the studio could be implemented on a regular basis, for example daily, particularly prior to the use of a given camera.
Examples of systems for identifying and tagging anomalies such as scratches or dust in a digital image are Shown in U.S. Pat. Nos. 6,233,364 B1 and 5,436,979. A system for a camera with a detachable lens is shown in U.S. Pat. No. 6,791,608 B1.